This invention relates to spinning machine having several spinning stations for spinning slivers to yarns and having transport devices for the withdrawal of the slivers from cans and for feeding them to the spinning stations, the transport devices comprising transport belts, the width of which is adapted to the thickness of one or several transport belts.
It is known (British Patent Document 1 015 780) to feed slivers to a ring spinning machine in cans. The slivers are withdrawn from the cans by way of rolls and are then guided to pairs of transport belts which receive the slivers between one another and transport them to the drafting units of the ring spinning machine.
It is an object of the invention to develop a spinning machine of the initially mentioned type in such a manner that relatively fine slivers with a size of from approximately Nm 0.4 to approximately Nm 0.8 can be fed without the occurrence of faulty drafts in the slivers during the transport.
This object is achieved according to preferred embodiments of the invention in that the transport belts are provided with tension inserts which are arranged at a distance to the closed lateral edges of the transport belts.
The invention is based on the recognition that a perfect feeding of the slivers without unintentional drafts will only be possible if the transport belts have such a high tensile strength that they themselves do not stretch during the travel from the cans to the drafting units because such stretching of the transport belts would lead to a drafting of the slivers and thus to a disturbance of the spinning operation. In this case, care is also taken at the same time that the inserts, particularly in the area of the lateral edges of the transport belts are not exposed because otherwise fibers may become hung up on them which may also be the reason for a disturbance of the spinning operation. This is reliably prevented by means of the closed smooth lateral edges covering the tension inserts.
In a further development of the invention, it is provided that the transport belts are strip-shaped blanks made of a web-shaped belt, the width of which amounts to a multiple of the width of the individual transport belts. In this manner, an economical manufacturing of the transport belts is possible which themselves have only a relatively small width. In a further development, it is provided that the belt, which is manufactured in a web-shape, is provided with tension inserts extending in its longitudinal direction, between which an insert-free intermediate space is left in each case. This intermediate space has the purpose of cutting the web-shaped belt into individual strip-shaped blanks for the relatively narrow transport belts. By means of this cutting, the inserts will then not be exposed so that smooth closed lateral edges exist in the case of the individual transport belts.
In a further development of the invention, it is provided that the tension inserts are embedded into a basic material made of plastic.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.